Performance monitoring and fault management functions are currently utilized to test the reliability of packet delivery over E-Line point-to-point Ethernet service. In a point-to-point service, if the ingress frame count over a period of time for one end point of the E-LINE does not match the egress frame count at the other end point for that period, there is frame loss. There is presently, however, no standard defined solution for multipoint-to-multipoint E-LAN networks. For such a multipoint service, unicast frames that ingress at one endpoint can egress at any other endpoint. Additionally, broadcast and multicast frames are also present which will ingress at one endpoint and egress at multiple endpoints. It becomes exceedingly difficult to match ingress and egress frame counts and to determine where, or if, frame loss is occurring.
One proposed solution utilizes Synthetic frame loss Measurements. This approach assumes that the synthetic frame behavior will be the same as the user frame traffic and uses statistical methods to derive a frame loss Ratio over a long period of time.
However, if there are n endpoints in a VLAN there will be n(n−1)/2 point to point loss measurement sessions required to determine a frame loss ratio between each end point. It turns out that in order to support the required accuracy for the statistical methods to reliably detect an error rate of 10−6 (which is the accepted threshold of reliability for mobile backhaul applications), the Synthetic frame loss Measurement method will need to send synthetic loss measurement messages every 100 ms. Therefore a VLAN with 8 endpoints in it will require 8(8−1)/2=28 sessions and 2(LMM+LMR)×10(100 ms rate)×28(sessions)=560 messages per second. Since all messages are processed by the host CPU of each Network Interface Device (NID) this requires quite a powerful CPU to handle this task in addition to all the other aspects of managing the NID and this rate must be supported deterministically under all CPU loading conditions.
For the reasons stated above and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the specification, there is a need in the art for improved systems and methods for loss measurement in E-LAN configurations.